Abstract

A new dorylaimid taxon, Vastnema crassicutaneum gen. et sp. nov., collected in natural habitats of Vietnam, is characterized, including morphological description, morphometrics, SEM observations, and molecular (18S-, 28S-rDNA) analyses. Vastnema gen. nov. is distinguished and separated from its relatives by a combination of key traits: large size (body 4.79–6.35 mm long), lip region tapering and continuous with the adjoining body, very short neck (b-ratio 6.3–8.7), presence of a peculiar uterine differentiation, pre-equatorial (V = 38–44) vulva, and 45–58 stomata-like ventromedian supplements. The new species is characterized by its three-layered cuticle, 12.5–15.5 µm thick at the anterior region; lip region 26–31 µm wide; odontostyle 49–60 µm long, or 1.8–2.0 times the lip region diameter; neck 627–888 µm long; pharyngeal expansion occupying 46–49% of the total neck length; uterus complex and 571–804 µm, or 3.2–4.3 body diameters long; longitudinal vulva; tail short and rounded in both sexes (39–56 µm, c = 98–140, c’ = 0.5–0.7); and spicules 138–160 µm long. Both morphological and molecular data support a close relationship of the new taxon with some Labronematinae representatives but also reveal that internal and external relationships of Dorylaimidae might be more complex than traditionally assumed.

Addeddate

2025-03-12 20:02:31

Bhl_virtual_titleid

165999

Bhl_virtual_volume

v.101:no.2 (2025)

Call number

10_3897_zse_101_144271

Call-number

10_3897_zse_101_144271

Foldoutcount

0

Genre

article

Identifier

vastnemacrassic101vuta

Identifier-ark

ark:/13960/s2b0nrjzkh8

Identifier-bib

10_3897_zse_101_144271

Identifier-doi

10.3897/zse.101.144271

Issue

2

Ocr

tesseract 5.3.0-6-g76ae

Ocr_detected_lang

en

Ocr_detected_lang_conf

1.0000

Ocr_detected_script

Latin

Ocr_detected_script_conf

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Ocr_module_version

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Ocr_parameters

-l eng

Page_number_confidence

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Page_number_module_version

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Page_range

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Pages

14

Pdf_degraded

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Pdf_module_version

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Possible copyright status

In copyright. Digitized with the permission of the rights holder.

Ppi

300

Source

Zoosystematics and Evolution 101(2)

Year

2025

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